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| author | Damien Le Moal <damien.lemoal@wdc.com> | 2018-11-30 08:36:24 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2018-12-17 05:53:06 +0300 |
| commit | f9824952ee1cd02ae1a74e35e0e8653f8a4db772 (patch) | |
| tree | e19b1ff205fa3d64994cd71b6a1ef1fcafe94f32 /Documentation/block | |
| parent | 38a3499f6d0cb15bd673e517b0656807e22bfd24 (diff) | |
| download | linux-f9824952ee1cd02ae1a74e35e0e8653f8a4db772.tar.xz | |
block: update sysfs documentation
Add the description of the zoned, nr_zones and chunk_sectors sysfs queue
attributes to Documentation/block/queue-sysfs.txt. The description of
the zoned and chunk_sector attributes are mostly copied from
ABI/testing/sysfs-block (added a typo fix). While at it, also fix a
typo in the description of the io_poll_delay attribute.
nr_zones description is also added to ABI/testing/sysfs-block and
contact email address updated for the zoned attribute.
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'Documentation/block')
| -rw-r--r-- | Documentation/block/queue-sysfs.txt | 29 |
1 files changed, 28 insertions, 1 deletions
diff --git a/Documentation/block/queue-sysfs.txt b/Documentation/block/queue-sysfs.txt index 2c1e67058fd3..39e286d7afc9 100644 --- a/Documentation/block/queue-sysfs.txt +++ b/Documentation/block/queue-sysfs.txt @@ -64,7 +64,7 @@ guess, the kernel will put the process issuing IO to sleep for an amount of time, before entering a classic poll loop. This mode might be a little slower than pure classic polling, but it will be more efficient. If set to a value larger than 0, the kernel will put the process issuing -IO to sleep for this amont of microseconds before entering classic +IO to sleep for this amount of microseconds before entering classic polling. iostats (RW) @@ -194,4 +194,31 @@ blk-throttle makes decision based on the samplings. Lower time means cgroups have more smooth throughput, but higher CPU overhead. This exists only when CONFIG_BLK_DEV_THROTTLING_LOW is enabled. +zoned (RO) +---------- +This indicates if the device is a zoned block device and the zone model of the +device if it is indeed zoned. The possible values indicated by zoned are +"none" for regular block devices and "host-aware" or "host-managed" for zoned +block devices. The characteristics of host-aware and host-managed zoned block +devices are described in the ZBC (Zoned Block Commands) and ZAC +(Zoned Device ATA Command Set) standards. These standards also define the +"drive-managed" zone model. However, since drive-managed zoned block devices +do not support zone commands, they will be treated as regular block devices +and zoned will report "none". + +nr_zones (RO) +------------- +For zoned block devices (zoned attribute indicating "host-managed" or +"host-aware"), this indicates the total number of zones of the device. +This is always 0 for regular block devices. + +chunk_sectors (RO) +------------------ +This has different meaning depending on the type of the block device. +For a RAID device (dm-raid), chunk_sectors indicates the size in 512B sectors +of the RAID volume stripe segment. For a zoned block device, either host-aware +or host-managed, chunk_sectors indicates the size in 512B sectors of the zones +of the device, with the eventual exception of the last zone of the device which +may be smaller. + Jens Axboe <jens.axboe@oracle.com>, February 2009 |